This invention relates to a copier adapted for composite copying whereby coping is effected twice or more on a single sheet of copy paper and more particularly to such a copier which automatically adjusts its magnification according to the change in size of the paper caused by the previous copying operation thereon.
In the case of a two-side copying process, an image is transferred first onto one side of the copy paper and then a similar process is repeated on the other side. In other words, copying is effected twice on a single sheet of copy paper. In the case of a composite copying process, copying is effected onto a part of the paper first and the same or another image is transferred onto another part on the same side of the paper. This is repeated any number of times. After each copying, however, the paper is passed through a fixing device to have the transferred image fixed. If the fixing process is carried out by a pressure fixing method, the paper tends to become stretched during the process but if it is done thermally, the paper tends to shrink.
In the case of such a multiple copying process, therefore, the effective magnification changes after each copying process because of the change in the size of the processed copy paper. This means that the obtained image may appear distorted, mismatched, or misaligned. No copier, however, has been developed to eliminate this problem.